ZrSiN film was selected as diffusion barrier and sputtered on polished titanium substrate with RF reactive magnetron sputtering. XRD, XPS and SEM results reveal that the ZrSiN diffusion barrier is a nano-composite that consists of nano-crystallite ZrN and amorphous-like SiNx phase. The results also show that in the surface of Ti substrate without ZrSiN diffusion barrier, there is Ti oxides, however, in the surface of Ti substrate with ZrSiN diffusion barrier, there is not Ti oxides and does only Zr, Si, N and O. This proves that ZrSiN diffusion barrier protect the Ti substrate against oxidation. The three-point bending test results prove that ZrSiN diffusion barrier significantly improves the bonding strength between Ti substrate and porcelain. The ZrSiN diffusion barrier with high Si content results in higher adhesion strength of the Ti/porcelain. This indicates that amorphous Si-N phase of ZrSiN diffusion barrier improves its barrier property.